1. Field of the invention.
The invention relates to an electro-surgical excisor used for excising a tissue specimen from the transformation zone of the uterine cervix.
2. Description of related art.
Using loop electrodes on the end of a handle for excising tissue from an organ, particularly the cervix, has been known in the art. However, most devices are limited in the control of the removal of damaged tissue.
Known related art includes an instrument for electro-surgical excision of the transformation zone of the uterine cervix depicted in U.S. Pat. No. 5,554,159 to Fischer. The electrode does incorporate a stop arm for control the depth of the entry of the endocervical portion of the instrument; however, the electrode is fixed at each end and extends in a straight line diagonally between the stop arm and the endocervical portion end. This instrument thereby excises a conically shaped portion of the organ and does not take into account the unique cervical shape of the individual. As such, it is likely that too much stroma or depth of the-organ undergoing the Loop Electrical Excision Procedure (LEEP) can be taken. The gross excision of the transformation zone, extra ectocervix and unnecessary stroma can result in excessive scarring, incompetent cervix and cervical stenosis. In addition, longer recovery periods and unnecessary discomfort for the patient are experienced as a result of using prior art instruments.
What is then needed is a device which is deformable concavely to conform to the unique shape of an individual""s cervix or organ, thereby allowing for the excision of the minimal amount of organ tissue. This can be accomplished by an instrument that peels away the epithelium leaving stroma substantially intact, thereby promoting faster recovery, less discomfort and alleviating unnecessary scarring and other problems associated with the use of prior art instruments.
The present invention is a configurable electrode instrument for use in loop electrical excision procedures. The invention comprises an elongate main body member having a distal end and a proximal end; the distal end of the elongate main body member further having an endocervical portion contiguous to and integrally connected to said distal end and extending therefrom.
The proximal end of the elongate main body member further has a contact portion connected to the elongate main body member and extending therefrom for operative engagement with an electro-surgical device and/or manipulator or connection. The endocervical portion has a laterally-oriented stop arm contiguous to the distal end of the elongate main body member and a longitudinal member extending from the stop arm and distal end of the elongate main body member, the stop arm for limiting the depth of insertion of the endocervical portion into an endocervix.
The stop arm has a first end hingedly connected at the distal end of the elongate main body member. An electrode extends generally diagonally from near a second end of the stop arm to near an outer end of the longitudinal member. The electrode is in electrical communication through the endocervical portion, the elongate main body member and the contact portion so as to electrically connect with the electro-surgical device.
Adjustment means for adjusting a rotational angle of the stop arm about its first end are provided. The adjusting means enables the configuration of the electrode to be varied from a generally minimally concave configuration to a substantially concave configuration. The electrode can be adjusted to be configured to an individual""s cervical shape, thereby allowing for a peeling excision of a transformation zone of an ectocervix, while leaving the stroma substantially intact.
The adjustment means is operatively engaged with the elongate main body member. This can be done with a manipulation member engaged with the elongate main body member which can used by the surgeon to make the necessary adjustments to form the electrode in the desired concave configuration. A linking member connects the second end of the stop arm to the manipulation member. When a surgeon wants to configure the electrode so as to obtain more concaveness, the surgeon would simply adjust the manipulation member so as to advance the linking member toward the endocervical portion, thereby rotating the free end of the stop arm toward the cervix. Similarly, if less concaveness of the electrode was desired, then the surgeon would adjust the manipulation member to retract it along the elongate main member, thereby rotating the free end of the stop arm away from the cervix.
There are several optional ways of providing the adjusting means, although a preferred method which would provide for generally infinite adjustments, is the incorporation of a concentric threaded nut around manipulation member and elongate main member, wherein when a surgeon rotates the nut, the manipulation member, which is slidingly engaged with the elongate main member, slides back and forth.
The elongate main body member is dimensioned to extend outwardly of a vaginal canal when the endocervical portion is inserted into the endocervix. In addition, the manipulation member is located such that it too extends outside the vaginal canal such that the electrode instrument, including the manipulation member may be manipulated externally of the vaginal canal by the surgeon.
The electrode is fastened to the endocervical portion at a point spaced inwardly from the outer end of the longitudinal member, and the opposite end of the electrode is fastened proximate the free end of the stop arm.